The present invention relates to polymer composites. More specifically, the present invention relates to polymer composites comprising a water-insoluble polymer and a water-sensitive alkylene oxide-based copolymer.
Water-sensitive polymers, i.e., water-soluble or water swellable, are commonly used in the manufacture of various personal care devices and medical devices which are intended to be used in contact with skin. The water-sensitive polymers function to provide lubricity to the device when it becomes wetted with an aqueous fluid such as water or a body fluid. Typically, the water-sensitive polymers are used in conjunction with water-insoluble polymers which function to provide the appropriate structural characteristics and mechanical integrity to the device for its intended use.
In order to provide an effective combination of a water-sensitive polymer and a water-insoluble polymer for use in making a personal-care device or medical device, it is desirable that the polymers be sufficiently compatible to provide a finished product having a high degree of compositional regularity. That is, when the polymers are not sufficiently compatible, segments of the article may be predominantly comprised of one polymer or the other polymer. This can lead to mechanical failures and to lack of lubricity where desired. Also, it is desirable that the lubricity characteristics are retained after repeated uses of the device.
One common personal care device which typically uses a water-insoluble polymer, e.g., polystyrene, and a water-sensitive polymer, e.g., polyethylene oxide, is a wet-shaving device, i.e., a razor. Typical shaving devices comprise a support structure supporting a blade member and an external skin-engaging portion in proximity to the blade member. The skin-engaging portion typically comprises a composite comprising a matrix of the water-insoluble polymer and the water-sensitive polymer. Polymer compatibilizers, as well as common shaving aids, e.g., vitamin E, aloe or various low-molecular weight polymers, are often included in the composite.
Typical medical devices which can be made lubricious include, for example, catheters, guide wires, endotracheal tubes and implants. Such articles are often comprised of water-insoluble polymers, such as polyethylene, polypropylene, polyvinylchloride and polyurethanes. A variety of approaches to introduce lubricity have been implemented. Coatings of mineral oils, silicone and various water-sensitive polymer coatings have been applied to medical devices to enhance their lubricity. In addition, water-sensitive polymers, such as polyethylene oxide, have been blended and co-extruded with water-insoluble polymers, such as described above, to provide lubricious polymer blends.
Despite the advancements in the art to provide lubricity to polymer devices, a common deficiency is that the devices typically lose their lubricious-when-wet properties after relatively few uses. According to U.S. Pat. No. 5,454,164, a typical shaving device may only retain its lubricious properties for three or four shaves. Accordingly, new polymer composites are desired which can be used to manufacture articles having enhanced lubricity characteristics. In particular, it is desired that such articles significantly retain their lubricity characteristics after repeated uses.
By the present invention, polymer composites are provided which comprise a water-insoluble polymer and a water-sensitive polymer. The water-sensitive polymer is a copolymer polymerized from one or more alkylene oxide compounds and one or more epoxy-functional compounds.
By virtue of the present invention, it is now possible to manufacture articles having lubricious-when-wet characteristics which can retain their lubricity characteristics after repeated uses. Examples of articles in which the polymer composites of the present invention can be employed include personal care devices, such as shaving devices, and medical devices, such as catheters.